Currently, post-catastrophe surveys are not uniquely tagged, so there is no way to identify or filter on these surveys using Nearmap APIs.

If you have an Australian Nearmap Post-Catastrophe subscription, you'll receive an email to let you know when a new event has been captured, and another email to let you know when the imagery has been published including a link to the relevant survey locations and dates.

If you want to compare pre- and post-catastrophe imagery using the Tile API, we've created a tutorial on using the Tile API & QGIS to view and compare imagery.